Factors associated with single versus multiple supernumerary teeth in a paediatric population: a cross-sectional study

Purpose Supernumerary teeth (ST) are developmental anomalies. However, factors associated with ST have not been extensively reported in the literature. The aim of the present study was to identify factors associated with single supernumerary teeth (SST) and multiple supernumerary teeth (MST) in a non-syndromic Brazilian sample. Methods A cross-sectional study was conducted with a convenience sample of 305 non-syndromic patients with ST seen over a 10-year period at a paediatric oral surgery service in Southeast Brazil. The outcome variable was the classification of ST as SST or MST. Covariates included age, race, sex, morphology, location, position, eruption status, orientation, associated complications, and treatment modality of ST. The Mann–Whitney test, chi-squared test, and both simple and multiple logistic regression analyses were performed. Results A total of 460 ST were identified among the 305 patients, with male predominance (68.2%). Mean age was 9.3 years. Most patients had SST (62.2%) and 37.8% had MST. ST were primarily located in the maxilla (93.1%), with fewer cases in the mandible or both arches. MST were strongly associated with specific position, eruption, orientation, clinical complication, morphological, and treatment characteristics ( p < 0.001). Conclusion Tuberculate and supplemental ST, palatal positioning, and eruption status were significantly associated with an increased likelihood of MST. Moreover, MST were associated with a greater risk of adjacent tooth displacement and greater need for combined orthodontic treatment and extraction.